1 /* 2 * Copyright (C) 2016 National Instruments Corp. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 */ 14 15 #include <linux/acpi.h> 16 #include <linux/device.h> 17 #include <linux/interrupt.h> 18 #include <linux/io.h> 19 #include <linux/module.h> 20 #include <linux/watchdog.h> 21 22 #define NIWD_CONTROL 0x01 23 #define NIWD_COUNTER2 0x02 24 #define NIWD_COUNTER1 0x03 25 #define NIWD_COUNTER0 0x04 26 #define NIWD_SEED2 0x05 27 #define NIWD_SEED1 0x06 28 #define NIWD_SEED0 0x07 29 30 #define NIWD_IO_SIZE 0x08 31 32 #define NIWD_CONTROL_MODE 0x80 33 #define NIWD_CONTROL_PROC_RESET 0x20 34 #define NIWD_CONTROL_PET 0x10 35 #define NIWD_CONTROL_RUNNING 0x08 36 #define NIWD_CONTROL_CAPTURECOUNTER 0x04 37 #define NIWD_CONTROL_RESET 0x02 38 #define NIWD_CONTROL_ALARM 0x01 39 40 #define NIWD_PERIOD_NS 30720 41 #define NIWD_MIN_TIMEOUT 1 42 #define NIWD_MAX_TIMEOUT 515 43 #define NIWD_DEFAULT_TIMEOUT 60 44 45 #define NIWD_NAME "ni903x_wdt" 46 47 struct ni903x_wdt { 48 struct device *dev; 49 u16 io_base; 50 struct watchdog_device wdd; 51 }; 52 53 static unsigned int timeout; 54 module_param(timeout, uint, 0); 55 MODULE_PARM_DESC(timeout, 56 "Watchdog timeout in seconds. (default=" 57 __MODULE_STRING(NIWD_DEFAULT_TIMEOUT) ")"); 58 59 static int nowayout = WATCHDOG_NOWAYOUT; 60 module_param(nowayout, int, S_IRUGO); 61 MODULE_PARM_DESC(nowayout, 62 "Watchdog cannot be stopped once started (default=" 63 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 64 65 static void ni903x_start(struct ni903x_wdt *wdt) 66 { 67 u8 control = inb(wdt->io_base + NIWD_CONTROL); 68 69 outb(control | NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL); 70 outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL); 71 } 72 73 static int ni903x_wdd_set_timeout(struct watchdog_device *wdd, 74 unsigned int timeout) 75 { 76 struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd); 77 u32 counter = timeout * (1000000000 / NIWD_PERIOD_NS); 78 79 outb(((0x00FF0000 & counter) >> 16), wdt->io_base + NIWD_SEED2); 80 outb(((0x0000FF00 & counter) >> 8), wdt->io_base + NIWD_SEED1); 81 outb((0x000000FF & counter), wdt->io_base + NIWD_SEED0); 82 83 wdd->timeout = timeout; 84 85 return 0; 86 } 87 88 static unsigned int ni903x_wdd_get_timeleft(struct watchdog_device *wdd) 89 { 90 struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd); 91 u8 control, counter0, counter1, counter2; 92 u32 counter; 93 94 control = inb(wdt->io_base + NIWD_CONTROL); 95 control |= NIWD_CONTROL_CAPTURECOUNTER; 96 outb(control, wdt->io_base + NIWD_CONTROL); 97 98 counter2 = inb(wdt->io_base + NIWD_COUNTER2); 99 counter1 = inb(wdt->io_base + NIWD_COUNTER1); 100 counter0 = inb(wdt->io_base + NIWD_COUNTER0); 101 102 counter = (counter2 << 16) | (counter1 << 8) | counter0; 103 104 return counter / (1000000000 / NIWD_PERIOD_NS); 105 } 106 107 static int ni903x_wdd_ping(struct watchdog_device *wdd) 108 { 109 struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd); 110 u8 control; 111 112 control = inb(wdt->io_base + NIWD_CONTROL); 113 outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL); 114 115 return 0; 116 } 117 118 static int ni903x_wdd_start(struct watchdog_device *wdd) 119 { 120 struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd); 121 122 outb(NIWD_CONTROL_RESET | NIWD_CONTROL_PROC_RESET, 123 wdt->io_base + NIWD_CONTROL); 124 125 ni903x_wdd_set_timeout(wdd, wdd->timeout); 126 ni903x_start(wdt); 127 128 return 0; 129 } 130 131 static int ni903x_wdd_stop(struct watchdog_device *wdd) 132 { 133 struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd); 134 135 outb(NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL); 136 137 return 0; 138 } 139 140 static acpi_status ni903x_resources(struct acpi_resource *res, void *data) 141 { 142 struct ni903x_wdt *wdt = data; 143 u16 io_size; 144 145 switch (res->type) { 146 case ACPI_RESOURCE_TYPE_IO: 147 if (wdt->io_base != 0) { 148 dev_err(wdt->dev, "too many IO resources\n"); 149 return AE_ERROR; 150 } 151 152 wdt->io_base = res->data.io.minimum; 153 io_size = res->data.io.address_length; 154 155 if (io_size < NIWD_IO_SIZE) { 156 dev_err(wdt->dev, "memory region too small\n"); 157 return AE_ERROR; 158 } 159 160 if (!devm_request_region(wdt->dev, wdt->io_base, io_size, 161 NIWD_NAME)) { 162 dev_err(wdt->dev, "failed to get memory region\n"); 163 return AE_ERROR; 164 } 165 166 return AE_OK; 167 168 case ACPI_RESOURCE_TYPE_END_TAG: 169 default: 170 /* Ignore unsupported resources, e.g. IRQ */ 171 return AE_OK; 172 } 173 } 174 175 static const struct watchdog_info ni903x_wdd_info = { 176 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, 177 .identity = "NI Watchdog", 178 }; 179 180 static const struct watchdog_ops ni903x_wdd_ops = { 181 .owner = THIS_MODULE, 182 .start = ni903x_wdd_start, 183 .stop = ni903x_wdd_stop, 184 .ping = ni903x_wdd_ping, 185 .set_timeout = ni903x_wdd_set_timeout, 186 .get_timeleft = ni903x_wdd_get_timeleft, 187 }; 188 189 static int ni903x_acpi_add(struct acpi_device *device) 190 { 191 struct device *dev = &device->dev; 192 struct watchdog_device *wdd; 193 struct ni903x_wdt *wdt; 194 acpi_status status; 195 int ret; 196 197 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); 198 if (!wdt) 199 return -ENOMEM; 200 201 device->driver_data = wdt; 202 wdt->dev = dev; 203 204 status = acpi_walk_resources(device->handle, METHOD_NAME__CRS, 205 ni903x_resources, wdt); 206 if (ACPI_FAILURE(status) || wdt->io_base == 0) { 207 dev_err(dev, "failed to get resources\n"); 208 return -ENODEV; 209 } 210 211 wdd = &wdt->wdd; 212 wdd->info = &ni903x_wdd_info; 213 wdd->ops = &ni903x_wdd_ops; 214 wdd->min_timeout = NIWD_MIN_TIMEOUT; 215 wdd->max_timeout = NIWD_MAX_TIMEOUT; 216 wdd->timeout = NIWD_DEFAULT_TIMEOUT; 217 wdd->parent = dev; 218 watchdog_set_drvdata(wdd, wdt); 219 watchdog_set_nowayout(wdd, nowayout); 220 ret = watchdog_init_timeout(wdd, timeout, dev); 221 if (ret) 222 dev_err(dev, "unable to set timeout value, using default\n"); 223 224 ret = watchdog_register_device(wdd); 225 if (ret) { 226 dev_err(dev, "failed to register watchdog\n"); 227 return ret; 228 } 229 230 /* Switch from boot mode to user mode */ 231 outb(NIWD_CONTROL_RESET | NIWD_CONTROL_MODE, 232 wdt->io_base + NIWD_CONTROL); 233 234 dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n", 235 wdt->io_base, timeout, nowayout); 236 237 return 0; 238 } 239 240 static int ni903x_acpi_remove(struct acpi_device *device) 241 { 242 struct ni903x_wdt *wdt = acpi_driver_data(device); 243 244 ni903x_wdd_stop(&wdt->wdd); 245 watchdog_unregister_device(&wdt->wdd); 246 247 return 0; 248 } 249 250 static const struct acpi_device_id ni903x_device_ids[] = { 251 {"NIC775C", 0}, 252 {"", 0}, 253 }; 254 MODULE_DEVICE_TABLE(acpi, ni903x_device_ids); 255 256 static struct acpi_driver ni903x_acpi_driver = { 257 .name = NIWD_NAME, 258 .ids = ni903x_device_ids, 259 .ops = { 260 .add = ni903x_acpi_add, 261 .remove = ni903x_acpi_remove, 262 }, 263 }; 264 265 module_acpi_driver(ni903x_acpi_driver); 266 267 MODULE_DESCRIPTION("NI 903x Watchdog"); 268 MODULE_AUTHOR("Jeff Westfahl <jeff.westfahl@ni.com>"); 269 MODULE_AUTHOR("Kyle Roeschley <kyle.roeschley@ni.com>"); 270 MODULE_LICENSE("GPL"); 271